The present invention relates to distributed processing and more particularly to interchange of data in communication system having one or more host processors connected for cooperative interaction with a plurality of intelligent terminals or work stations.
Cooperative processing is well known in the art, illustrative of which are systems such as those depicted in FIG. 1 hereof, wherein a host processor is operative in a purely reactive mode to requests for objects (data and processing routines) requested by the connected terminal/work stations. While such systems provide substantial economies of equipment by providing for the sharing of selected computational features at a consolidated level, (i.e., at a host processor) they nevertheless require two flows of information for each item communicated from the host to a connected terminal/work station:
(1) The initiation of a request at the work station communicated over a data link to the host; and
(2) Data generated or otherwise produced at the host and communicated over a data link back to the requesting terminal/work station.
When the host processor is busy, requests for information may await their turn in a queue, thereby resulting in significant delays. Moreover, even if there is no queue, and the request for data is responded to immediately upon receipt, there nevertheless is a loss of time occasioned by the need for the requesting terminal to transmit a request to the host together with loss of time involved in production of requested data and their communication by the host back to the terminal over the connecting link. Moreover, it is desirable further to improve the efficiency of time and equipment utilization in systems of the type described herein in order to provide a storage hierarchy within terminal work stations whereby the terminal work stations can anticipate the future need at the work station of certain types of data and or processing information (hereinafter referred to as "objects") and to have them stored at the work station so that such objects are available for utilization (display/processing) immediately upon request by the user without having to obtain them from the host, thereby substantially improving time efficiency and equipment utilization.